Cortical Bone Augmentation Versus Nerve Lateralization for Treatment of Atrophic Posterior Mandible: A Retrospective Study and Review of Literature.

Abstract

We sought to assess implant success/survival/failure rate following cortical autogenous tenting technique (CATT) versus inferior alveolar nerve transposition (IANT) in the posterior mandible. Patients who underwent these two procedures between 2007 and 2011 were analyzed. CATT was performed using lateral ramus block graft and implants were inserted simultaneously or after 4 to 6 months. In IANT, implants were placed simultaneously after nerve transposition with or without mental foramen involvement. Data regarding marginal bone level (MBL), pus discharge (PD), neurosensory dysfunction (NSD), implant mobility, and failure were collected. Success rate was measured based on Pisa Consensus. Independent sample t-test with a significance level of 0.05 was used to compare implant dimensions and MBL changes between the two techniques. A total of 118 patients with a mean age of 54.85 years were included. The mean follow-up after CATT and IANT was 37.97 and 18.51 months, respectively. The overall survival and success rates of dental implants in the CATT group were 98.73% and 71.52%, respectively. The corresponding values for IANT subjects were 98.74% and 94.56%, respectively. Implant length and diameter in IANT group were significantly longer and wider than implants used after CATT (p value < .001). MBL changes in both techniques were less than 1 mm (p value = .79). Two cases of NSD, seven PD, and two implant failures were found in the CATT group. For IANT patients, seven permanent NSD, two PD, two implant failures, and one mandibular fracture were documented. Both techniques had implant survival rates similar to implants placed in unaltered bone. A higher implant success rate, albeit with higher incidence of long-lasting nerve damage, was observed in the IANT group.